postgre SQL Connection String
danang setya pramanahave 2 version of it postgres://username:password@127.0.0.1:5432/dbname AND postgresql://username:password@127.0.0.1:5432/dbname
mongodb connection string
mongodb://username:password@127.0.0.1:27017/dbname?authSource=admin
flutter –no-sound-null-safety issu
goto your vs code , settings and type flutter run additional args and remove args --no-sound-null safety, and flutter will work